PROPOSED INCLUSION OF WORK PHYSIOLOGY IN FCE HEART RATE RESERVE METHOD. Guided Discussion by Theodore J. Becker PT, PhD Whitney L.

Transcription

1 PROPOSED INCLUSION OF WORK PHYSIOLOGY IN FCE HEART RATE RESERVE METHOD Guided Discussion by Theodore J. Becker PT, PhD Whitney L. Ogle PT, DPT

2 Background A Functional Capacity Evaluation (FCE) should predict full time work tolerance There are no universally accepted standards, methods, or procedures for predicting work time tolerance Commercial FCE protocols do not include scientific formulas for projection to an eight hour day (King, 1998) Use of 85% heart rate max (HR max ) as cut off during FCE While some FCE reports mention heart rate responses during testing, we have found that FCE conclusions were not based on objective physiological responses during testing (Becker, 2015)

3 Background & Purpose Analysis of heart rate response to activity is not a standard method in the determination of full time work tolerance in FCE protocols at this time The purpose of this guided discussion is to spark a conversation about the use of heart rate data in determining full time work tolerance during FCE testing

4 Historical Perspectives Heart rate response can be used to determine if work can be maintained throughout working time (Bonjer, 1962) Heart rate has been established as the preferred determinant of full time work tolerance as is a well established indicator of work physiology response (Garg & Hagglund, 1983) There are formulas to predict full time work that are completely independent of exercise fitness testing (Davies, 1966)

5 Heart Rate & FCE Testing A work physiology test is designed to impose strain upon the individual that is correlated with the demands of their work environment and the worker s ability Because typical day-to-day work is not performed at maximum aerobic capacity, there is no need to determine VO 2max for FCE Measuring the physiological response to required work tasks can assess the heaviness of a task and the sustainable capacity for the task completion Heart rate is one of the best indexes for this assessment because of the linear relationship between heart rate and stress of task (Davies 1966, Booyens 1960) Heart rate is also less invasive to test than VO 2

6 Physiological Strain and Work Duration Astrand (1960) reported that the upper limit of work tolerance for an eight hour work day is 50% of physical work capacity Since industrial work may involve both high and low intensities throughout the day, the upper limit of work tolerance should be less than 50% of physical work capacity (Jiang, 1984;; Kaudawitz 1998) Workload Percent Work Work Duration Heart Rate (bpm) Moderate <33% 8 hrs Heavy 34-50% 1-8 hrs Very Heavy 51-75% 20 min 1 hour Extremely Heavy >75% <20 min >150 From Jiang (1984) See also: Astrand (1960), Kodak (1986), AIHA (1971), Kroemer (2001), Williams (1964), Wilson (1995)

7 HRR Utility Have worker perform an individualized circuit matching the job demands and measure HR every 5 minutes The circuit should be longer than 5 minutes to ensure steady state heart rate If the circuit HR is at or below the expected work heart rate, the worker meets the cardiorespiratory requirement of the job. If the circuit HR is above the expected work heart rate or closer to max capacity, the shorter the length of time an individual can work

8 Conclusion FCE s should predict full time work tolerance Average expenditure for 8 hour work day is 33% Heart rate response to activity during FCE s is not standard practice BUT it is informative in making conclusions about work tolerance The HRR method takes resting heart rate into account (rather than simple %HR max ) so FCE conclusions are more reflective of the individual

9 References Astrand, P.O. & Saltin, B (1961). Maximal oxygen uptake and heart rate in various types of muscular activities. J App Physiol, 16(6), Astrand, P.O., Rohdahl, K., Dahl, I. & Stromme, S. (2003). Textbook of Work Physiology. (4 th Ed). Champaign, IL: Human Kinetics Becker, T.J., Ogle, W., Chadbourne, J., Andrews, K. (2015). Prevalence of Own Design functional capacity evaluation regarding work physiology science. Rehab Professional, 23(4), Becker, T.J. (2008). Functional capacity evaluations: The work physiology component for predicting full-time work. Directions in Rehabilitation Counseling, 18, Becker, T.J., Morrill, J.M. & Stamper, E. (2007). Applications of work physiology science to capacity test prediction of full time work: eight hour work day. Rehab Professional, 15(4), Bonjer, F. (1962). Actual energy expenditure in relation to physical work capacity. Ergonomics, 5, Davies, C. (1966). Heart rate and respiration in relation to working capacity in man (Doctoral Dissertation). University of Edinburgh, Edinburgh, Scotland Garg, A., Chaffin, D., Herrin, G. (1978). Prediction of metabolic rates in manual materials handling jobs. Am Industrial Hygiene Assoc J, 39(8), Jiang, B. (1984). Psychophysical capacity modeling of individual and combined manual materials handling activities (Doctoral Dissertation). Texas Tech University, Lubbock, TX, USA. Kaudawitz, H.R. (2004). Work standard assessment using heart rate monitoring. IIE Solutions, King, P., Tuckwell, N. & Barrett, T. (1998). A critical review of functional capacity. Physical Therapy, 78(8), Kodak Ergonomics Group. (1986). Ergonomic design for people at work. New York, NY: Van Nostrand Reinhold. Kroemer, K. & Grandiean, E. (2001). Fitting the Task to the Human. Philadelphia, PA: Taylor & Francis. Tanaka, H., Monahan, K. & Seals, D. (2001). Age predicted maximal heart rate revisited. J Am College Cardiol, 37(1), Williams, J. (1964). Setting Job Standards and Selecting or Evaluating Workers for Physiological Work Measurement. Los Angeles, CA: University of California Los Angeles Wilson, J. & Corlett, E. (1995). Evaluation of Human Work. London, England: Taylor & Francis.